Legal Custody of Tachograph Files

Obligations, Cybersecurity Risks, Penalties, and Best Practices for 2026

The legal custody of tachograph files has evolved from a simple administrative task into a critical pillar of corporate legal security. In an environment where digitalization is accelerating under the 2026 EU transport regulations, failing to maintain an integral filing system is the fastest route to losing your company's "good repute" and facing fleet-wide license suspensions.

Comprehensive Custody and Compliance Analysis:

  • Forensic Nature: Understanding .DDD and .TGD files.
  • Data Life Cycle: Mandatory retention periods.
  • Responsibility Matrix: Company vs. Driver liability.
  • Risk Assessment: Fines and loss of honorability.
  • Logistics Cybersecurity: Protection against data loss.
  • TachoTools Protocol: The gold standard in digital custody.

Why Tachograph Files are Considered Forensic Evidence

Digital tachographs do not just record hours; they generate cryptographic evidence. Every downloaded file contains a unique digital signature that ensures data has not been altered since its original recording in the Vehicle Unit (VU) or the driver card. In the current legal context, these files hold the same evidentiary weight as a notarized document during labor inspections or audits by the EU Transport Authorities.

Anatomy of .DDD, .TGD, and .V1B/C Formats

Depending on the country of vehicle registration or the driver's nationality, the format may vary, with .DDD being the predominant European standard. When you choose to open digital tachograph files, you are accessing an event log that includes: Card identification, driving periods, breaks, speed profiles, and, in newer models, GPS/GNSS positions.

The key to legal custody lies in the digital signature. If a file is opened and saved with unauthorized software that alters a single bit of information, the digital signature breaks. A file with a broken signature is equivalent to a tampered document: it lacks legal validity and can be interpreted as an attempt at fraud in transport records.

Data Inviolability in the Smart Tachograph V2

With the arrival of the Second Generation Smart Tachograph, custody becomes more complex. Files now record automatic border crossings and load/unload operations. Effective legal custody involves not just storing the file, but ensuring that the security certificates (public keys) required to verify those signatures are updated in your card readers and management software.

The Mandatory Data Retention Calendar

Regulation (EC) No 561/2006 and national European laws establish strict deadlines that every company must follow to avoid "documentary voids." Failure to meet these timelines is considered a direct obstruction of inspection duties.

🏢 Transport Companies

1 - 5 Years

The legal minimum for transport is 1 year (365 days), but due to Social Security and Labor laws and the statute of limitations for fiscal offenses, we recommend custody for 5 years to protect the company's civil liability.

🚛 Drivers (Owner-Operators)

28 - 365 Days

You must carry the data for the last 28 days (moving to 56 days under the Mobility Package) on board the vehicle. However, for compliance audits, you must keep annual copies at your registered office.

Download Frequency: The Foundation of Safe Custody

You cannot safeguard what you do not download. The law mandates downloading the driver card every 28 days and the vehicle unit every 90 days. However, a company with high-security protocols will perform weekly downloads or use remote tachograph download systems to feed their custody archive in real-time, minimizing data loss risks due to hardware failure.

Warning: The Risk of Data Overwriting

Driver card memory is finite. If you exceed 28 days without downloading and securing the file, the oldest data will begin to be deleted to make room for new records. Deleted data cannot be recovered for custody, leading to automatic fines during inspections.

The Cost of Negligence: Fines and Regulations in 2026

In 2026, administrations have tightened inspection criteria under a "zero tolerance" policy for information opacity. Failing to present a requested file in the correct format is no longer seen as a simple oversight; it is considered an obstruction of the regulatory framework.

Fine Schedule for Custody Failures

Fines for failing to preserve records or delivering them in unreadable or corrupted formats are among the highest in the system:

  • Serious Infringements: Range from €601 to €1,000 for missing records of a single day or driver.
  • Very Serious Infringements: Can reach €4,001. This occurs when the lack of files prevents the control of driving times or suggests manipulation.
  • Loss of Good Repute: This is the most feared "ghost" penalty. Accumulating custody-related infractions can trigger the loss of honorability, leading to the suspension of the transport license.
The Presumption of Labor Violations

It is a common mistake to think custody only matters to Roadside Inspectors. Labor Authorities use .DDD files as the master evidence for work hour tracking. Without these files, the administration automatically assumes maximum hours have been exceeded. Legal custody is your only line of defense against wage claims from workers or unions.

Logistics Cybersecurity: Why the USB Drive is No Longer Safe

Historically, many companies kept custody on a local hard drive or a USB stick in the office. In 2026, this practice is an unacceptable risk. The rise in Ransomware attacks targeting SMEs in the logistics sector has caused thousands of companies to lose their historical files, leaving them defenseless against retroactive inspections.

Data Security: Manual Custody vs. TachoTools Cloud
Threat / Risk Manual Custody (PC/Local Server) TachoTools Custody (Secure Cloud)
Hardware Failure Total Risk. A hard drive crash means permanent loss of years of data. Geographic Redundancy. Data replicated across multiple servers (99.9% Backup).
Ransomware Attacks Vulnerable. If your office PC is infected, your .DDD files will be encrypted and held for ransom. Security Isolation. AES-256 encryption and ironclad access protocols.
GDPR Compliance Doubtful. Files contain sensitive driver data without auditable access control. Total. Access logging and strict adherence to European data protection laws.
Availability Limited. Files can only be accessed if you are physically in the office. Global Access. Manage files from anywhere via App or Web.
The "Integrity Proof" Protocol

Robust legal custody is not just about "storage." The TachoTools protocol includes an integrity validation at the moment of upload. If a file is corrupted due to a card read error, the system detects it immediately. This allows the manager to request a new download while the driver is still available, preventing the error from becoming a fine months later.

Cybersecurity Note: In 2026, transport inspectors are trained to detect DDD files that have been "re-saved" or modified using text editing software. TachoTools preserves the digital chain of custody intact, ensuring the file presented is the exact original generated by the tachograph.

Liability Matrix: Who is Accountable to the Law?

A recurring question in transport legal consultations is the delimitation of responsibilities. Is it the driver's fault if they don't download their card? Or is the company the only one paying the fine? Under the 2026 framework, responsibility is shared, but the burden of proof lies with the company.

The Company as the Custody Guarantor

The transport license holder is ultimately responsible for ensuring data exists and is truthful. The company must not only "save" the files but actively supervise that downloads occur within legal timeframes. If a driver refuses to provide their card, the company must prove it has provided all technical means, such as remote downloading, to prevent that loss.

The Driver: Responsibility for the Physical Medium

The driver is the physical custodian of their card. Their obligation is to ensure the card is in optimal reading condition. During a roadside inspection, the driver must present records for the current day and the previous 28 days. If a reading error occurs, the driver must perform manual printouts so the company can custody them later.

Custody Protocol for Theft or Loss

If files are lost due to vehicle theft or catastrophic tachograph failure, legal custody is supplemented by:

  • Police Report: Must specifically mention the loss of digital records.
  • Workshop Certificate: If the failure was technical, an authorized workshop must issue an "Impossibility of Data Recovery" report.
  • Manual Entry: Drivers must reconstruct activity on tachograph printouts. These physical documents become the object of legal custody for the required year.

The New Dimension of Custody: Smart Tachograph V2

The transition to the Smart Tachograph Version 2 (G2V2) is not just a hardware upgrade; it is a change in data density. Legal custody now covers information that didn't exist before, raising the risk of "incomplete data" infractions.

GNSS Positioning and Borders

New .DDD files automatically record every time a vehicle crosses a border and every three hours of accumulated driving. In a 2026 inspection, agents cross-reference legal custody data with toll records and European camera systems. If your custody system cannot process these new GNSS data blocks, you might be presenting "unreadable" files, incurring heavy penalties.

Load and Unload Records

Regulations now mandate recording load and unload operations. These events are saved in the card and vehicle memory. Efficient management through a digital management platform ensures these events are downloaded correctly. Failing to custody these logistics milestones leads to fines for missing labor activity records.

The 28 vs 56 Day Trap

Remember that under the Mobility Package, the obligation to show roadside records doubles. This means on-board custody is now much more critical. If the card fails and there is no recent backup on the company server, the driver faces an unavoidable penalty for missing historical records.

The TachoTools Protocol: Beyond Simple Storage

At TachoTools, we do not view legal custody of tachograph files as a "file warehouse." we treat it as a Dynamic Digital Vault system. When you upload a file to our platform, a forensic validation protocol is activated, ensuring your company is always ready for a surprise audit.

Automatic Integrity Auditing

Our analysis engine verifies the file's digital signature in the first second of upload. If it detects an incomplete file or a structural error in the .DDD, the system issues a red alert. This allows you to fix the problem before the legal deadline expires.

Defense Reports for Inspections

TachoTools allows you to generate a Digital Logbook. This report consolidates years of custody into a structured PDF document with timestamps and integrity validation, facilitating the inspector's work and proving your company meets the highest 2026 regulatory standards.

Frequently Asked Questions about Legal Custody

Custody obligation is joint. The new company owner inherits the responsibility to preserve files for the last 365 days and the labor history of the staff. Using multi-company management like TachoTools facilitates this transition without data loss.
Absolutely. The law does not distinguish vehicle ownership, but rather who holds the company card inserted during the activity. If you operate a rental vehicle, you must download and custody the vehicle unit (VU) file before returning it.
Yes, as long as they comply with ISO/IEC 7816. TachoTools is compatible with all European formats, ensuring unified custody for international fleets.

Conclusion: Custody as a Strategic Asset

Ignoring the legal custody of tachograph files is an incalculable financial risk. In the era of connected mobility, transparency is your best marketing tool and your most powerful legal shield.

Do not settle for "saving" files; ensure integrity, availability, and data intelligence. With TachoTools, turn a legal obligation into a competitive advantage.

This article was drafted according to current EU Mobility Package regulations. For specific legal advice, please contact our legal department.